Process for producing demulsifying agents for refining petroleum oil



Patented June 12, '1e2s..

UNITED STATES PATENT OFF 1,673,045 ICE.

EDWIN D. GRAY, OF RICHIVIOND, CALIFORNIA,

ASSIGNOR, BY MESNE ASSIGNMENTS,

TO STANDARD OIL COMPANY OF CALIFORNIA, OF SAN FRANCISCO, CALIFORNIA, A

CORPORATION OF DELAWARE.

PROCESS FOR PRODUCING DEM ULSIFYING AGENTS FOR REFINING PETROLEUM OIL.

No Drawing.

This invention relates to the art of treating petroleum oils and refers partlcularly to the art of manufacturing lubricating oils.

In the manufacture of lubricating oils 5 from petroleum oil, certain reaction prod-- 10 the treatment has been separated from the -oil.

In the subsequent neutralization and washing of the acid-treated oil, said reaction products (together with other substances which may have been present in the original crude stock) cause the formation of emulsions. The production of these emulsions hinders the effective neutralization of the lubricating oils and complete removal of the organic acids, materially re- 20 duces the yield of the finishedoil throughloss of oil removed or drawn on" as emulsified oil, causes the oil to darken in color during the brightening operations, and produces a lubricating oil -.-Znstable in color, These troubles are especially pronounced when the stock used to produce this lubricat- 7 ing oils is from an asphaltic or mixed-base crude, and when treating said crudesat best only an imperfect separation of the emultained by the standard methods of treatment.

The most troublesome emulsions are encountered in the production of the heavier motor oils, and particularly in the roduc. tion of heavy steam cylinder oils. Eecause of the formation of such emulsions, it is extremely difiicult to neutralize such oils through a caustic or lye treatment. In the lye treatment of the heaviermotor'oils, it is frequently necessary to employ. 'alcoho or other expensive agents in order to carry in solution the emulsion-forming reaction products and thereby break or prevent the formation of emulsions. In the production of heavy steam cylinder oils, caustic or lye treatment is practically impossible due to the formation of emulsions, and,therefore, it is common practice in the art to employ a distillation operation after'the acid treat ment. Such a. distillation can be carried out only with a high'rate of deterioration and corrosion of the 'distillating equipment and will result in the production of a dark Application filed October 4, 1923. Serial No. 666,458.

sified constituents from the oil can be ob-- a caustic or lye treatment could be employed on an acid-treated cylinder out forming emulsions, then the use of a cutter stock could be eliminated.

Heretofore, various soaps of organic acids, especially those extracted from petroleum acid sludge, have been used to overcome the emulsion troubles referred to.

oil stock with- These soaps have been found to be. only partially satisfactory as demulsifying agents and impart to the oil treated certain suspended or colloidal substances which pro- I I A duce cloudiness in the treated oil. To remove this cloudiness from the treated oil, a higher temperature and longer time is required for the brightening operation than Whensuch demulsifying agents are not employed and therefore results in an increase in' the oxidation of the oil, lowering of the color, and an altering of the natural bloomof the oil. It appears that only certain of the soaps produced from acid sludge are suitable for breaking or preventing emul sions and that these always exist with certain heavier sulfonated compounds which counteract the beneficial effect of the useful soaps or demulsifying agents. Furthermore, the heavy sulfonated bodies which have heretofore been used in the treating of petroleum oils, of caustic for their require a large amount neutralization, and this tends to increase the consistency, density or viscosity of the soaps and render them less effective in preventing the, formation of emulsions.

The primary object of this invention is to produce a demulsifying agent which is less mulsifying' agent imparting to the oil a cloudy appearance and increasing the temperature and time reguired during the rightening operation, oxidizing of the oil and us decreasing the preserving the color and natural bloom of the oil while attaining the desired increased yield.

-Anotlierobject of this invention is to pro- I vide 'aprocess for producing a demulsifying employed.

terials which will produce I have further discovered that these desired materials can be separated from the heavy sulfonated bodies in an acid sludge by a process wherein the acid sludge may be utilized in the treatment of certain other petroleum oils and thus simultaneously effect a decrease in the cost of treating such oils and result in the production of the improved de-. mulsifying agent. The objects and advantages of this invention will be readily comprehended from a description of a preferred process embodying the invention and, therefore, there is hereafter described one example of a process embodying the invention.

I prefer to first treat a relatively viscous oil with sulfuric acid to remove a part of those constituents which polymerize upon the addition of acid or otherwise form tarry matter in the sludge produced. Such preliminary acid treatment onv the relatively viscous oilmay be carried out in one or in a number of applications of the acid depending upon the amount of such constituents to fembodiment of my be removed from the'oil. When such preliminary acid treatment is used, th e acid is applied in proportions of about one-half pound of acid per gallon of oil treated, and after each treatment the sludge produced is allowed to'settle and is drawn off. This preliminary sulfuric acid treatment has been found tov increase the quality of the sludge thereafter-produced and to result in the production of a superior quality of demulsifying agent, although it is not intended to limit the invention in its broadest aspect to such preliminary treatment, as such preliminary treatment is essential only to the preferred invention.

from which the detheoil is then- To pyrglduce the sludge g agent is produced,

. materials from which the treated with a concentrated sulfuric acid. The term concentrated is used to indicate any sulfuric acid over 97% in strength, and includes fuming sulfuric acids, the use of fuming sulfuric acid being preferable. The acidsludge produced from the action of this concentrated sulfuric acid upon" the oil is then withdrawn and utilized in the production of the demulsifying agent. Since a concentrated sulfuric acid is employed, the acid sludge thus derived will be found to have a considerable potential, strength relative to other petroleum oils less treated by sulfuric acid. This acid sludge is then applied to a medium or light lubricating oil distillate. This later oil distillate may or may not be given a preliminary acid treatment before the treatment with the acid sludge. \Vhen such preliminary acid treatment is used, I add from'one-eighth to one-half pound of 66 B. acid per gallon of distillate treated and then settle and draw off the'sludge produced "before the application of the acid sludge. The nature of the light lubricating oil used is found to have an important effect upon the nature of the demulsifying agent produced; thus, if a. light-weight lubricating oil is used, a demulsifying agent will be thereafter produced which is best suited for the treatment of heavy motor oils, whereas, if the still heavier steam cylinder oil is to be treated by the demulsifying agent, it is found preferable to contact the acid sludge with a slightly heavier lubricating oil distillate,

such as those which produce medium-weight lubricating oils. In either case, it is found that if a lubricating oil distillate having a viscosity in excess of at 210 F. is em- .ployed, the resultant'demulsifying agent will be too dense or viscous for the best results in demulsifying the heavy lubricating oil. About one-half pound. of sludge per gallon of oil treated produces satisfactory results.-

Through contact between the acid sludge and the oil treated thereby, the acid sludge removes certain constituents from the oil, thickening the sludge, and the materials which produce the demulsifying agent are taken up by the oil and held either in solution or suspension and can be separate along with the oil from theresultant acid sludge. rials are separated from the bulk of theheavy sulfonated bodies which in the customary demulsifying soaps inhibit the action of the-demulsifying agent.

In the preferred process, the oil is then treated with fromone-eighth to one-half pound of 66 B. sulfuric acid. The sludge from such treatment is then removed and the demulsifying agent is to be produced are still retained in the The oil is then treated the oil the materials which to separate from form the demul- In this maiiner such desired mateis then permitted to settle out and is drawn off. This treatment substantially eliminates from the oil the heavy sulfonated bodies which were not removed with the previous sludges and leaves the oil free from such heavy sulfonated bodies and in a condition whereby the demulsifying agent can be obtained in a purified form. The oil is then neutralized. Upon neutralization the materials which form the demulsifying agent are washed from the oil forming an aqueous solution or suspension. This resulting aqueous solution is the improved demulsifying agent which we have found especially adapted to the treatment of lubricating oils and particularly for the treatment of heavy motor oils and steam cylinder oils.

The demulsifying agent may be used for treating heavy lubricating oils in a variety of manners, but preferably is accomplished in the following manner: After a sulfuric acid treatment of such oils, caustic soda or other alkali is applied to the acid-treated oil until the same is nearly neutralized. The sediment from this treatment is withdrawn and then the oil is treated with the demulsifying agent in such quantities as to effect rapid separation after the complete neutralization of the oil, the separation being facilitated by the presence of added water. In this latter treatment, those bodies in the oil which tendto form emulsions enter into the aqueous demulsifying solution and can be readily withdrawn from the-oil.

An important advantage of this invention resides in the fact that, through the use of I the deinulsifying agent produced, the brightening of the heavy lubricating oils may be carried out at a low temperature and in a short period of time. Thus through the use of such agent I have been able to reduce the temperature necessary for the brightening operation at least 10 to 15 F. and simultaneously reduced the time required for the brightening operation as much as 40%. By

this reduction in the temperatureand the period of time required for the brightening operation, a material reduction in theoxidation of the oil is effected and a better-colored oil is obtained, having the natural bloom of the oil.

A further advantage of the invention is that through t e use of the demulsifying agent I am ab e to successfully treat the heaviest cylinder oils with caustic or other neutralizing reagent and thereby eliminate the necessity of a reducing distillation upon the oil in theacid state. Moreover, through 'viscous petroleum oil to the the use of such demulsifying agent,'heavy cylinder oils may be treated with caustic soda or like material, and thus obviating any necessity of adding a cutter stock prior to the acid treatment.

It will thus be seen that by the production of a demulsifying agent of the correct consistency, density or viscosity for the'oil to be treated thereby, not onl are advantageous results obtained in $16. treatment and production of various lubricating oils, but this is accompanied by a utilization of materials of little value and Without carryrials. 7

While I have herein described the preferred example of the invention, it is understood that various modifications may be made in the details'of the process herein described without departing from the spirit, of the invention, and this invention is not, therefore, limited to the preferred example described, but is of the scope set'forth in the accompanying claims.

I claim 1. A process of producing a demulsifying agent comprising, treating a petroleum sulfonate sludgecontaining some free sulfuric acid with a lubricating oil stock, separating such treated oil from the sludge, partially neutralizing the oil with an alkali, Withdrawing the resultant sediment, neutralizing the oil and washing the rwultant demulsifying agent therefrom.

2. The process of producing a demulsif ing agent, which includes first treating a viscous petroleum oil with sulfuric acid to remove a part of the constituents which polymerize with the addition of sulfuric acid, then treating such oil with a sulfonating agent to yield a sludge, contacting the acid sludge from the latter treatment with a petroleum oil, separating the thickened sludge from such oil, neutralizing the oil and washing therefrom the produced demulsifying agent.

3. The process of producing a demulsi'fying agent, which includes first removing from a viscous petroleum oil a part of those eonstituents which polymerize on the addiconcentrated sulfuric acid, subjecting a lubricating oil distillate to the resultant acid sludge from said 'treatment, partially neutralizing the second treated oil, withdrawing the resultant sediment, neutralizing the oil,

and washing from the oil the resultant demulsifying agent.

4;. The process of producing a demulsifying agent suitable for the treatment of lubricating oils, which consists in subjecting a a'ction'of a sulfonating agent to yield a sludge, contacting the acid sludge resultant from said treatment with a lubricating oil distillate, the

viscosity of which in the finished state does lubricating oil distillate, separating .said oil not exceed 85 at 210 F., and neutralizing from the sludge, treating the separated oil said acid sludge beingapplied to said second with a neutralizing agent only in suflicient lubricating oil stock while it still contains quantity to produce incomplete neutralizasuch a strength of unexhausted sulfuric acid tion, removing the neutralizing agent, then as to be capable of reacting upon said second treating the partly neutralized oil with adlubricating oil stock, and washing from the ditional neutralizing agent and removing oil the resultant demulsifying agent. the resultant demulsifying agent from the 5. The process of producing a demulsifyoil. i ing agent which comprises treating a viscous Signed at Richmond, California, this 28th petroleum oil with concentrated sulfuric day o Sept.,1 923. 7 acid, bringing the resultant sludge containing some free sulfuric acid in contact with EDWIN D. GRAY. 

